Mold for plastic perforated diaphragms



Oct. 16, 1962 E. P. AGHNIDES 3,058,158

MOLD FOR PLASTIC PERFORATED DIAPHRAGMS Original Filed Aug. 4, 1959 I507117 FIG. 6,. I60 A,

Q /2|b 20b FIG. 7. l5b

33 gm FIG. a.

/lli 2H, 2: '34? m 48 I56 OR %4? Elle P. Aghnldes 39 35c ATTORNEYSUnited States Patent Ofi 3,058,158 Patented Oct. 16, 1962 3 1358 158MQLD FGR PLASTIC P ERI ORATED DIAPHRAGMS Elie l2. Agirrzides, 46 W. 54thSt, New York, N.Y. @riginal application Aug. 1959, Ser. No. 831,588, nowPatent No. 2,998,931, dated Sept. 5, 1961. Divided and this applicationJuly 27, I961, Ser. No. 134,557 8 Glaims. (Cl. 1842) This inventionrelates to molds for producing perforated plastic diaphragms for devicesfor aerating water.

An object of the invention is to provide an improved mold forefiiciently manufacturing perforate plastic disks for faucet aerators.The invention may be applied to permanent and integral faucetconstructions as well as to attachments for existing faucets.

These and other novel features of the invention will be betterunderstood by considering the following detailed description and byreference to the accompanying drawings, in which:

FIGURE 1 is a top view of the plastic perforate disk member for anaerator.

FIGURE 2 is a cross-sectional view of mold sections showing the diskmember of FIGURE 1 as it appears in its molding cavity.

FIGURE 3 is a vertical cross-sectional detail of a portion of said diskmember as viewed in section 3-3 of FIGURE 1.

FIGURE 4 is a transverse cross-sectional detail view of the portion ofthe disk member taken on the line 44 of FIGURE 3.

FIGURE 5 is a vertical cross-sectional detail view illustrating aportion of a further improved plastic perforated disk member constructedin a modified form in accordance with the present invention.

FIGURE 6 is a transverse cross-sectional detail view taken on line 66 ofFIGURE 5.

FIGURE 7 is a vertical cross-sectional detail view illustrating stillanother form of perforate disk member constructed in accordance with thepresent invention.

FIGURE 8 is a transverse cross-sectional detail View taken on line 88 ofFIGURE 7.

FIGURE 9 is a perspective detail illustrating a method of making the pinportion of the mold.

FIGURE 10 is a sectional detail of a modified form of mold and diskmember therein.

One form of plastic perforated disc to be molded according to theinvention is shown at in FIGURE 1.

In practice, the disk 15 may include three substantially concentric rowsof passageways or perforations 16, and the two radially outermostannular ribs 17 on the upstream surface of disk 15 are disposed so thatthey cover and partially close the inlet ends of the perforations 16 ofthe two radially outermost concentric rows. The innermost row ofperforations 16 have their entrance openings extending into the sides ofpin 30, as shown in FIG- URE 1, or alternatively may extend into aninnermost rib (not shown), adjacent pin 30.

Another embodiment of the present invention is shown in FIGURE 5, thisform of the invention comprising a disk 15a formed with a plurality ofconcentric rows of perforations or passageways 16a extendingtherethrough, and further provided with a plurality of concentricannular ribs 17a disposed to cover the rows of perforations 16a at theirupstream ends. In this construction the annular ribs 17a are of the samewidth as the passageways 16a, the latter projecting into the ribs 17a asubstantial portion of the height of the ribs, providing opposedopenings 20a in each side of the ribs where the passageways 17aintersect and are coincident with the radially inner and outer sidewalls of the ribs. As a result, jet streams of water entering thepassageways 16:: from both sides of each annular rib 17a, impinge uponeach other thereby creating an extensive turbulence so that the waterissues from the passageways 16a into the aeration chamber in the form ofstreamlets having greatly impaired coherence. As illustrated in FIGURE5, the upstream surfaces of the ribs 17a may be beveled or rounded forstreamline flow of water into openings 20a in the sides of the ribs.

The disc 15a may have one or more circular rows of holes 16a. In eithercase the holes 1611 may be elongated so as to extend toward theneighboring holes 16a of the same circular row; and indeed if the partsare suitably supported the holes 16a may be elongated to such extentthat they joint together forming a narrow circular opening. Moreover,two or more holes of a given row may be joined to form an elongatedslot. In the modifications suggested in this paragraph, ribs 17a andopposed openings 20a remain unchanged.

In still another embodiments of the invention, illustrated in FIGURES 7and 8, the disk 15b is formed with a plurality of concentric rows ofpassageways or perforations 16b, the upstream ends of which extendpartially into annular ribs 1%, each passageway 16]) having its upstreamsides coincident with the opposite side walls of the respective ribsinto which it projects, providing opposed openings 2012 in each side ofthe ribs adjacent the passageways, is similarly to the form of theinvention shown in FIGURE 5. In this embodiment, however, the upstreamend of the passageway is formed with a pair of opposed steps 21b wherebywater forced through the opposed openings 20b of each passageway isgiven added turbulence by the stepped construction so that the jetstreams of water passing over the stepped construction impinge upon eachother thereby creating added turbulence with the result that the jetstream then entering the aeration chamber will be further broken up intostreamlet-s of more greatly impaired coherence. The upstream surfaces ofribs 1712 may be beveled or rounded for streamlining the flow of wateraround the annular ribs and into openings 20b in the sides of the ribs.

In each of the embodiments of the invention, the preferred shape ofpassageways '16, 16a, and 16b is shown as cross-sectionallysubstantial-1y square, trapezoidal or rectangular, the radially outersurfaces of the passageways being on the same curvature as the radiallyouter surfaces of the annular ribs, so that the ends of the passagewayswhich project into the ribs are coincident with the side surfaces of theribs, leaving clear openings in the sides of the ribs. In the form ofthe invention shown in FIGURES 5 and 7 the radially inner surfaces ofthe passageways are similarly on the same curvature as the radiallyinner surfaces of the annular ribs.

Optimum conditions or aeration and coherence of the issuing stream ofwater may be determined by experimenting with difierent sizes ofpassageways 16, different thicknesses of disk 15 and differentdimensions for the entrance opening 20 and stop 2.1. These dimensionsare found to vary with the diameter and longitudinal dimen sion of theaeration chamber 32 and spacing of screens 22 and 23, as well as thesize of wire and mesh of the screen.

The plastic disk member 15 may be injection molded in a mold as shown inFIGURE 2 in which an upper mold section 34 meets with a lower moldsection 35 to define a cavity of the same shape as the disk member to bemolded therein. A sprue 36 is formed in the mold wall, preferablycommunicating with the portion of the cavity for molding projection 30.The sprue is formed with a reverse draft formed by outwardly flaringsurfaces, so that when the mold is parted for extraction of the plasticdisk member, the plastic material at the top margin of the projectionwill be broken off.

The mold cavity may be filled by injection molding therein in a mannerwell-known in the art, through sprue 36, a molten plastic moldingmaterial, such as polyethylene or a copolymer of vinyl and vinylidenechlorides. These plastic materials are preferred compositions in view oftheir toughness, elasticity, ease of accurate molding, ability to form agood seal with metallic surfaces with which they come into contact, andtheir ability to withstand corrosion and to resist the building upthereon of scale, such as normally forms on surfaces exposed to flow ofhot water. A number of other plastic compositions are suitable, however,for use in disk member 15, for example, phenolic resins, nylon and otherthermosetting and thermoplastic materials which have a sufliciently highsoftening point as not to be unduly softened by contact with hot waterat the temperature at which the aerator is to be subjected.

In the molding of plastic products heretofore manufactured by means ofmolding operations in which a pin is employed to form a passageway orother aperture through the plastic material, it has been the practice tohave the end of the pin abut flush against the surface of the matingmold member, or to project into a tight fitting socket or recess in themating mold member. In the use of the abutting mold surfaces, a flash isusually formed between the end of the pin and the mating mold surface.This requires an additional operation for the removal of flash where thesame is detrimental to the utility of the product as in the presentcase. In the prior art example where the pins extend into recesses, thepins, becoming displaced or distorted by pressure and handling of themold, soon lose the super-accuracy required for molding minutelydetailed tight fitting parts, and as soon as a pin becomes bent, it willbreak instead of entering its tight fitting recess. In the present case,the pins 37 for molding passageways 16, 16a or 16b, project into, butnot entirely through, annular cavities or grooves 42 in the molddesigned to produce annular ribs 17, 17a or 17b; thus the free spacearound the ends of the pins avoids the need for super-accuracy andeliminates pin breakage. Furthermore, the wiping and Wedging contactbetween the sides of pins 37 and the sides of ribs 38 in the mold formolding the annular grooves between annular ribs 17, prevents theformation of any flash in the openings between passageways 16 and saidannular grooves at the sides of ribs 17.

As shown in FIGURES 1 to 10 inclusive, passageways 16, 16a and 16b maybe uniform in Width both laterally and radially. In some instances ithas been found advisable, however, to flare these passageways outwardlyin a downstream direction, to increase turbulence of the jet streams ofwater passing therethrough for the purpose of more greatly impairingtheir coherence and incorporating a greater quantity of air mixed withthe water in the aeration chamber. A detail of a mold and portion of adiaphragm embodying this modification is shown in FIGURE 12, in whichthe upper mold section 34c is formed with an annular groove 420 intowhich the uniform end section 44 of pin 370 projects part way. Thepassageway molding pin 370 is then tapered outwardly toward lower moldsection 350 to provide a flared passageway 16c in diaphragm 150. Theflared side 45 may be on a radial side or both radial sides of thepassageway 16c and may be on one or both lateral sides of saidpassageway (not shown). Corresponding sides of pin 37c will be providedwith a beveled surface 46 to form such flared passageway 16c to producea divergence of the issuing streamlets of water.

An eflicient manner of manufacturing the mold sections 34 and isaccomplised by machining grooves and recesses in the mold sections, asillustrated, the pins 37 being machined in the ends of the tubularsections 39. The form of pins 37 employed for molding passageways 16, asshown in FIGURES to 6 inclusive, are formed on their ends with steps4ft. The pins for molding passageways 165, FIGURE 9, are similarlyformed with pairs of steps or slots in the ends of the pins (not shown).The tubular members 39 with pins 37 machined on one end are thenpress-fitted into grooves 41 in the lower section 35 of the mold,different diameters of tubular members 39 being fitted into concentricgrooves 41 of corresponding diameters to provide the concentric rows ofpins 39 in the mold, and corresponding concentric rows of perforationsor passageways 16, 16a, 16b or 166 in respective disks 15, 15a, 15b and15c.

In the form of the invention shown in FIGURE 10, pins 370 for producingflared passageway are formed in the end of a tubular member 39c having abeveled portion for molding beveled surface 4-6. The continuous end oftubular member 390 may be force-fitted into a groove (not shown) inlower mold section 35c, or as shown in FIGURE 10 the lower mold sectionmay be made up of a plurality of tightly fitting tubular ring members47, 3%, 43, etc. This system may also be employed in the building up ofthe lower mold section 35 if so desired.

It will be seen that, in accordance with this invention, the novel andimproved faucet aerator has been con structed for producing a soft,continuous, coherent, bubbly, oxygenated stream of water emerging fromthe aerator, resulting from greater turbulence and finer division ofwater particles in the jet streams of water passing through the noveltype of perforated disk. The new and improved design of molded plasticdisk affords added advantages in the facility of accurate and economicalproduction; the avoidance of corrosion and scale formation; and thefacility for cleaning out any foreign particles deposited from thewater. The novel combination of lateral passageways extending verticallyin the periphery of the disk and the downwardly directed openings in theperiphery of the casing in communication with the lateral passageways,provided a construction which will still direct the stream of waterdownwardly in the event the downstream screens are clogged, whereas theprior types of aerators having laterally extending air-inlet openings,will direct streams of water laterally if the streams below the air andwater mixing chamber become clogged with foreign matter. The new methodof molding the perforated plastic disk, whereby the perforation moldingpins in one mold section, extend into grooves in the opposing moldsection, with the ends of the pins and two or three sides of the pinsfree of contact with the opposing mold section, affords a noveleconomical molding process avoiding the production of flash at the endsof the perforations and the accompanying additional labor of removingsuch flash. The improved mold also embodies the novel feature ofproviding concentric annular rows of perforationforming pins havingsubstantially square, trapezoidal or rectangular cross-sections, whereinthe pins are produced on the ends of tubular members, the latter thenbeing fitted into grooves in the molds. By providing perforationmoldingpins having a substantially square, trapezoidal or rectangularcross-section, the pins can be formed as segments of annuli with theradially inner or outer segmental annular surface of a pin projectingfrom one mold section coincidentally contacting the side of an annulargroove or rib of the same radius in the opposed mold section, to moldclear openings free of flash.

While there have been described above what are presently believed to bethe preferred forms of the invention, variations thereof will be obviousto those skilled in the art and all such changes and variations whichfall within the spirit of the invention are intended to be covered bythe generic terms in the appended claims, which are variably worded tothat end.

This application for patent is a division of my copending applicationS.N. 831,588 filed August 4, 1959, now

US. Patent No. 2,998,931 granted September 5, 1961, for Faucet Aerators.

While there have been described above what are presently believed to bethe preferred forms of the invention, variations thereof will be obviousto those skilled in the art and all such changes and variations whichfall within the spirit of the invention are intended to be covered bythe generic terms in the appended claims, which are variably worded tothat end.

The foregoing new and inventive features of construction are defined inthe appended claims.

I claim:

1. A mold for molding plastic perforated diaphragms of the type used inwater faucet aerators, comprising relatively upper and lower moldsections enclosing a cylindrical molding cavity, concentric annular ribsand a groove therebetween in the cavity surface of said upper moldsection for molding complementary annular grooves and a rib in therelatively upper surface of said diaphragm, perforation forming pinshaving an arcuate sector-shaped form and being substantially rectangularin cross-section, arranged in an annular row in said lower mold sectionconcentrically and axially alined with the groove in said upper moldsection, said pins projecting partially into said annular groove in theupper mold section with the upper ends of said annular row of pinsformed with a central concentric slot for molding radially inner andouter steps at the ends of said perforations molded in said annular ribin the upper surface of said diaphragm, said pins having a radial widththe same as the radial width of said groove and having their radiallyinner and radially outer arcuate boundaries in tight contact laterallywith the respective radially outer and radially inner sidewalls of saidannular ribs in said upper mold section, the opposed contacting arcuatesurfaces being adapted to mold opposed lateral orifices through thesides of said annular rib of said diaphragm, said orifices communicatingwith said perforations to form water passageways through said diaphragm,the tightly contacting lateral arcuate surfaces thereby eliminating anyflash or overflow which would obstruct the perforations.

2. A mold for molding plastic perforated diaphragms of the type used infaucet aerators, comprising relatively upper and lower mold sectionsenclosing a cylindrical molding cavity, an annular groove and rib in thecavity surface of said upper mold section, perforation forming pinshaving an arcuate sector-shaped form and being substantially rectangularin cross-section arranged in an annular row in said lower mold sectionconcentrically and axially alined with the groove in the upper moldsection, said pins projecting partially into the annular groove in theupper mold section in overlapping engagement therewith, the overlappingends of said pins having at least one arcuate boundary in tight contactlaterally with a sidewall of said annular rib in said upper moldsection, the upper ends of said pins being formed with a step on theside of the pin in contact with a sidewall of the groove in the uppermold section, the tightly laterally contacting arcuate surfaces of saidrib and pins being adapted to mold lateral orifices through saiddiaphragm to communicate with said perforations, the stepped ends of thepins molding steps in the upper ends of the perforations adjacent saidlateral orifices to provide a restricted throat in the perforationsspaced from the contacting pin and groove surfaces, to eliminate flashin the throat of the perforations.

3. A mold for molding plastic perforated diaphragms of the type used inwater faucet aerators comprising upper and lower mold sections enclosinga mold cavity, concentric annular ribs and a groove in the cavitysurface of said upper mold section for molding complementary annulargrooves and a rib in the relatively upper surface or said diaphragm,perforation forming pins having an arcuate sector-shaped form and beingsubstantially rectangular in cross-section arranged in an annular row insaid lower mold section concentrically with the groove in said uppermold section, said pins projecting partially into said annular groove inthe upper mold section with the uper ends of said pins having a radialwidth the same as the radial width of said groove and having theirradially inner and radially outer arcuate boundaries in tight contactlaterally with the respective radially outer and radially innersidewalls of said annular ribs in said upper mold section, the opposedcontacting arcuate surfaces being adapted to mold opposed lateralorifices through the sides of said annular rib of said diaphragm, saidorifices communicating with said perforations to form water passagewaysthrough said diaphragm, the tightly contacting lateral arcuate surfacesthereby eliminating any flash or overflow to obstruct the perforationsthrough said diaphragrn.

4. A mold for molding plastic perforated diaphragms of the type used infaucet aerators, comprising upper and lower mold sections enclosing amolding cavity, an annular groove and rib in the cavity surface of saidupper mold section, perforation forming pins having an arcuatesectorshaped form and being substantially rectangular in crosssectionarranged in an annular row in said lower mold section, said pinsprojecting partially into the annular groove in the upper mold sectionin overlapping engagement, the overlapping ends of said pins having atleast one arcuate boundary in tight contact laterally with a sidewall ofsaid annular rib in said upper mold section, the tightly laterallycontacting arcuate surfaces of said ribs and pins being adapted to moldlateral orifices through said diaphragm to communicate with saidperforations without any flash being formed to obstruct theperforations.

5. A mold for molding plastic perforated diaphragms of the type used inwater faucet aerators, comprising relatively upper and lower moldsections enclosing a cylindrical molding cavity, concentric annular ribsand a groove therebetween in the cavity surface of said upper moldsection for molding complementary annular grooves and a rib in therelatively upper surface of said diaphragm, perforation forming pinshaving an arcuate sector-shaped form and being substantially rectangularin cross-section, arranged in an annular row in said lower mold sectionconcentrically and axially alined with the groove in said upper moldsection, said pins projecting partially into said annular groove in theupper mold section, said pins each having at least one of its arcuateboundaries in tight contact radially with a sidewall of said annulargroove in said upper mold section, the ends of each of said pins beingformed with a step adjacent the contact area with the sidewall of saidgroove for molding a step at the ends of said perforations extendinginto said annular rib in the upper surface of said diaphragm, thecontacting arcuate surfaces and steps in the ends of said pins beingadapted to mold stepped orifices through the sides of said annular ribof said diaphragm, said orifices communicating with said perforations toform passageways through said diaphragm, with a restricted throatadjacent said step in the upper end of said perforations, the tightlycontacting arcuate surfaces and stepped pin ends eliminating anyformation of flash which would obstruct the perforations.

6. A mold for molding plastic perforated diaphragms of the type used infaucet aerators, comprising relatively upper and lower mold sectionsenclosing a cylindrical molding cavity, an annular groove in the cavitysurface of said upper mold section to mold a rib in the top of saiddiaphragm, an annular groove in the cavity surface in said lower moldsection concentrically and axially alined with the groove in the uppermold section, a tubular insert fitted into the groove in said lower moldsection, an upper portion of said tubular insert being slotted to forman annular row of perforation forming pins in said molding cavity, saidpins having an arcuate sector-shaped form and being substantiallyrectangular in cross-section, said pins projecting partially into theannular groove in the upper mold section in overlapping engagement withthe side walls of said groove when said mold is closed, the overlappingends of said pins having at least one arcuate boundary in tight contactlaterally with an arcuate sidewall of said annular rib in said uppermold section, the upper ends of said pins being formed with a step onthat side of the pin which is in contact with the sidewall of the groovein the upper mold section, the tightly laterally contacting arcuatesurfaces of said groove sidewall and said pins being adapted to moldlateral orifices through said diaphragm to communicate with saidperforations, the stepped ends of the pins molding steps in the upperends of the perforations adjacent said lateral orifices to provide arestricted throat in the perforations spaced from the contacting pin andgroove surfaces, to eliminate flash in the throat of the perforations.

7. A mold for molding plastic perforated diaphragms of the type used inwater faucet aerators, comprising relatively upper and lower moldsections enclosing a cylindrical molding cavity, a concentric annulargroove in the cavity surface of said upper mold section for molding acomplementary annular rib in the relatively upper surface of saiddiaphragm, perforation forming pins having an arcuate sector-shaped formand being substantially rectangular in cross-section, said pins beingformed in an annular row in the end of a tubular insert and arranged ina groove in said lower mold section concentrically and axially alinedwith the groove in said upper mold section, said pins projectingpartially into said annular groove in the upper mold section when saidmold is closed, said pins each having at least one of its arcuateboundaries in tight contact radially with a sidewall of said annulargroove in said upper mold section, the ends of each of said pins beingformed with a step adjacent the contact area with the sidewall of saidgroove for molding a step at the ends of said perforations extendinginto said annular rib in the upper surface of said diaphragm, thecontacting arcuate surfaces and steps in the ends of said pins beingadapted to mold stepped orifices through the sides of said annular ribof said diaphragm, said orifices communicating with said perforations toform passageways through said diaphragm, with a restricted throatadjacent said step in the upper end of said perforations, the tightlycontacting arcuate surfaces and stepped pin ends eliminating anyformation of flash which would obstruct the perforations.

8. A mold for molding plastic perforated diaphragms of the type used inwater faucet aerators, comprising upper and lower mold sectionsenclosing a molding cavity for molding said diaphragms, an annulargroove and rib in the cavity surface of said upper mold section,perforation forming pins having an arcuate sector-shaped form and beingsubstantially rectangular in cross-section arranged in an annular row insaid lower mold section, said pins projecting partially into the annulargroove in the upper mold section in overlapping engagement, theoverlapping ends of said pins having at least one arcuate boundary intight contact laterally with a sidewall of said annular rib in saidupper mold section, the tightly laterally contacting arcuate surfaces ofsaid rib and pins being adapted to mold lateral orifices through saiddiaphragm to communicate with said perforations without any flash beingformed to obstruct the perforations, said pins tapering outwardly fromsaid groove contacting area toward said lower mold section to moldperforations which flare outwardly in a downstream direction tofacilitate divergence of the jet streams formed by said perforations.

References Cited in the file of this patent UNITED STATES PATENTS2,369,291 Frank a a1. Feb. 13, 1945 2,415,395 Ulrich Feb. 4, 19472,477,368 Gits July 26, 1949 2,541,923 Huxham Feb. 13, 1951 2,890,490Morin June 16, 1959

